Techniques of changing allocation of torques transmitted to front and rear drive wheels at the time of acceleration and at the time of deceleration are known. For example, in Japanese Laid-Open Patent Publication No. 2005-41383, the proportion of torques transmitted to the rear wheel and the front wheel is switched to 6:4 at the time of acceleration, the proportion of the torques transmitted to the rear wheel and the front wheel is switched to 1:1 at the time of motion at a constant speed, and the proportion of torques transmitted to the rear wheel and the front wheel is switched to 4:6 at the time of acceleration. By changing allocation of the torques transmitted to the rear wheel and the front wheel at the time of acceleration and at the time of deceleration, it is possible to suppress idling or locking of the wheels. The inventor conducted a further study for suitably allocating the torques transmitted to the front drive wheels and the rear drive wheels, and achieved the present invention.